Whitewoods can indeed be dried relatively fast. But there speed drying and there is speed drying. When we're talking of 'speed drying a wood', you are looking for gradually lowering the moisture content in a period of maybe four or five weeks. If you were to put the wood in the windy Sahara, the wood will be drying so fast on the surface, that it will check since the inner wood is still soaking wet. Think of your dehumidifier as the windy Sahara: the wood can dry too rapidly.
Drying wood depends on many factors, but the most easily influenced factor is the thickness of the wood you want to dry. Wood dries from the surface, so the inner wood will stay moist the longest. You can speed up the drying process tremendously by reducing the staves to a smaller thickness. A 2"x4" dries twice as fast as a 3"x3". The staves are currently very thick, and if you don't do anything with them, it WILL take at least one year before they are fully dry. If you rough them out somewhat (to near-floor tillered dimensions, but leave them wider) on a band saw, with an axe or drawknife, you're looking at two or three months drying time.
It is important to note that this holds true for ANY wood; not just hickory, nor only whitewoods. However, whitewoods are easier to speed dry than tropical hardwoods or woods such as osage/mulberry. The bark you left on the back, also slows the moisture down. This is great for woods that are sensitive to checking when (speed) drying, but is not needed for easy to dry whitewoods. I would therefore advice you to remove the bark carefully, and thin the stave enough to get it just bending an inch.Put the wood indoors (possibly near the dehumidifier if you live in a moist environment, but I personally don't think this machine is necessary, nor is a hot box). I prefer a bedroom or attic; a garage or cellar are often too moist for speed drying. Wait for about four weeks and you can commence up to floor tillering. Once the bow has been floor tillered, I'd put it aside for another additional week of drying. This will drive the last bit of moisture out. This is also the point where you can weigh the stave, to see if it looses any weight (=moisture) in a few days. When the stave stops loosing any weight a few days in a row, the wood has reached equilibrium moisture content (EMC).
Be very careful you don't damage the wood underneath the bark. That will be the back of your bow and must be undamaged. The bark is much softer than the wood, and it is therefore important you FEEL the tools you're using. A drawknife will eat the bark with no problems, but it will require more effort to cut the wood. If you're removeing the bark with a drawknife, it should be easy without too much energy involved. As soon as you suddenly have to apply more pressure on the tool, you're probably cutting the wood and must stop immediately. Dull tools can be better for bark removal. A dull drawknife, scraper and course sandpaper.
If you have a lot of wood, you could choose to deliberately sacrifice one stave and make a bow today - from green wood. You must then always remember the wood is still wet, so the bow will take a lot of set, and shoot sluggish. The bow might break after a few weeks, when the woods dries (dry wood is more likely to break than green wood). But you could have a shootable bow by the end of the day...this might keep your mind occupied while the rest of your (better) staves dries.